In 1996, a movie starring Stephen Baldwin and Pauly Shore called "Bio-Dome" came out. They played characters that think they're finding a mall but discover that they're inside a biodome. A biodome, or biosphere, is a man-made, closed ecological system. This means that every waste produced by an organism have to be used by another organism within the biosphere. They've been used to conduct experiments with the idea that a closed system would be a necessary way of life for long-term space living. On the space station, for example, everything the astronauts and cosmonauts need has to be transported with them or delivered later. Initially we'd have to transport supplies to get a space colony going too, but that would be expensive to continue indefinitely. So a viable space colony would have to eventually be self-sufficient.
The first biosphere was built in Russia in the mid-1960s. It used chlorella algae to recycle the air breathed by its occupants. They also grew crops for food. BIOS-3 was used until 1984 and its longest occupied term was 180 days. It was never a fully closed system, however. Biosphere-2 (Earth is the original biosphere) was built in the United States in the late 1980s and had two main missions as well as some smaller experiments.
On its second mission, the biosphere not only contained not only crops for food, but other plants, as well as animals. It ended abruptly in September 1994, after 10 months. The mission was ultimately a failure. Animals died (although many insects flourished), oxygen levels dropped, people got hungry, but most significant of all, they fought and formed factions. The psychological component of being sealed in with your colleagues can't be denied. Ultimately Biosphere-2 is thought of by some as a "successful failure." It didn't achieve its mission, but we did learn a lot in the process. It doesn't look like any of us will be living in self-sufficient biospheres of our own anytime soon, though.